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Science Year of the Bioeconomy
Sowing knowledge, harvesting food
Cassava has the potential to sustainably secure food supplies in Africa. However, the yields are too low. An international team of researchers wants to change this – with improved plants and drone flights.
Super tuber
Cassava conquers the menus of trendy restaurants. Prepared like chips, the carbohydrate-rich tuber is a welcome alternative to potatoes. Things are different in Africa: cassava is an important staple food for the people there. The plant is very well adapted to the tropical climate: in the rainy season, the plant stores so many nutrients in its roots, which are as thick as arms, that it can survive the five-month dry period. After the end of the dry season, as soon as the soil is no longer hard and the plant has replenished its underground storage, the up to three-metre-high plant is harvested – with all its valuable carbohydrates. This is what makes the plant so popular as a food.
Low yield
With almost 50 million tons per year, Nigeria is the largest producer of cassava, but the harvest yield is not very efficient. “If you look at the situation here, in agricultural practice, farmers create 70 to 80 per cent of the maximum possible yield. With Nigerian cassava, it is only about 20 per cent,” explains Prof. Dr. Uwe Rascher from the Jülich Institute of Bio- and Geosciences (IBG-2). More water, more arable land or the use of expensive technology to increase yields are difficult to achieve. However, if the plant were more robust and higher in yield, cassava could contribute to food security in precisely those areas where this has been lacking.
The CASS project
An international team of scientists is working on a variety of the cassava plant that is even better adapted to West African conditions and delivers higher yields. In the Cassave Source-Sink (CASS) project, Jülich scientists are conducting research in collaboration with colleagues from Friedrich-Alexander-Universität (FAU) Erlangen, who are coordinating the project, ETH Zurich and the International Institute of Tropical Agriculture, among others, in Ibadan in southwest Nigeria. CASS is financed by the Bill & Melinda Gates Foundation.
Airborne research
In the field trial in Nigeria, the CASS team is testing various cassava varieties. The researchers have access to around 500 varieties, which were created in crossbreeding experiments involving the four most frequently used varieties. During the tests, Jülich experts observe the aerial part of the plant. “We want to measure, in the course of the seasons, how and where the plant grows and how well it photosynthesises,” explains Uwe Rascher. A drone developed at Jülich is used to document the growth of more than 9,000 plants: it photographs the plants from the air. A specially modified software analyses these images and creates 3D models from them. Using these, the researchers can observe exactly how certain cassava types grow. This is a method that can also be used to study the growth of other food plants such as yam or millet.
Technology as a seed
Dr. Anna van Doorn is at the heart of these activities. The former employee of Uwe Rascher now works at the cassava experimental station in Nigeria. “Only when we understand how the plant grows under the local conditions can we try to improve it in a targeted way,” she explains. Anna von Doorn will be accompanying on-site research over the next three years and flying the camera drone, for which she played a major role in the development of hardware and software at Jülich. She also hopes to soon be able to involve Nigerian students in her work. This is an important step for Uwe Rascher: “We want to do research with local partners and only introduce technologies and processes that our partners in Africa can use sustainably. If the new processes can then be routinely carried out in the producing regions, we were successful as a research institution.”
Texts: Martha Peters/Jannis Lindner
Off to Africa!
African adventure? No, that’s not how Dr. Anna van Doorn would describe her departure for Nigeria. “The really exciting thing here is our research,” says the 32-year-old plant researcher, who has been living and researching on a campus of around 1,000 hectares near the megacity of Ibadan since March. In the huge research fields full of cassava, her attention is fully focused on a two-hectare area that is located directly on the campus. There are also accommodations, sports facilities and a supermarket there, and in the evening, the Dutchwoman meets up with friends to barbecue. “Basically, my working conditions and everyday research life here are not that different,” she says. “And working with the Nigerian colleagues is simply a pleasure. They are open, relaxed and always in the best of moods – and absolute cassava experts from whom I learn a lot.” At the same time, van Doorn knows that some things here are different after all. “For example, I could catch malaria here anytime, and although I can tolerate thetropical climate quite well, the working days in the research field are often extremely hot!”
For three years, the Jülich plant researcher from IBG-2 had regularly flown to the African country to measure the growth of cassava plants in a test field using a drone. She is now working for another three years on site at the International Institute for Tropical Agriculture (IITA). There, in the “Cassava Source-Sink” (CASS) project funded by the Bill& Melinda Gates Foundation, she is researching the up to five-meter-high plants with an international team. Cassava is one of themost important staple foods for the people of West Africa. “Nigeria produces more of it than any other country in the world, but the yield per hectare is rather low,” says van Doorn. “We are trying to find a more robust and higher-yielding variant of the plant that can then be used by local farmers.”
At home in the world
Anna van Doorn finds working in foreign countries and cultures enriching and hasalready done research in Japan, Ghana and Brazil for extended periods of time. For the CASS project, Prof. Uwe Rascher from IBG-2 had, at that time, specifically been looking for someone who was willing to move to another continent for a longer period. “That suited me pretty well,” remembers the plant researcher and smiles. She received specific training in Jülich and then went to Africa with her knowledge.
When she came to Forschungszentrum Jülich from the Netherlands, however, shehad never flown a drone before. She taught herself how to use all the finer pointsof this technology within a month – and within a short time, she also familiarised herself with the other materials and technology that now shape her everyday life in Africa. “We want to understand where in the cassava and at what point in the growth cycle the most carbohydrates can be found so that the root is more nutritious when harvested.” To do this, she takes hundreds of high-resolution photos with the drone, from which 3D models of the plants are then created. At Jülich, van Doorn co-developed the hardware and software especially for this application. The important thing is to keep the technology simple enough so that when in use in Nigeria, they themselves can do repairs quickly: it can take weeks to get spare parts or even a new drone there. So far, only once did a drone break down completely – when a truck accidentally levelled it.
Learning from each other
Van Doorn sees the project as a great opportunity for knowledge transfer: “In Germany, agriculture is highly precise. Hardly any water or nutrients are wasted here, there is a lot of automation. I am looking for ways to apply our technology and knowledge in Nigeria – and at the same time, I profit from the people’s experience here with the cassava plant.” In the end, the intention is for local farmers to be able to use the technologies and processes in the producing regions sustainably and without support from abroad. To ensure that this will be achieved, Uwe Rascher is currently strengthening his Jülich project team with twonew positions. And Anna van Doorn? She has her very personal goal in Africa always clearly in mind: “Once the research can be continued by the Nigerian colleagues alone, I will be superfluous here as a scientist. Then I can move on.”What are you researching
From "intern", the staff magazine of Forschungszentrum Jülich
Jannis Lindner
Photos: Forschungszentrum Jülich/Onno Muller, IITA/Ismail Y Rabbi, COLOA Studio, Cat Act Art/Shutterstock.com